This invention relates to apparatus and method for false twisting yarn, principally continuous multiple-filament synthetic yarn, such as to texturize or impart certain physical characteristics thereto. The type of apparatus to which the present invention in its broadest aspects is directed, usually involves heat setting of the false twist in the yarn, there often later being a removal of the false twist after a cooling of the yarn, such that the yarns take on a texturized, natural fibre appearance and character.
More particularly, this invention relates to multiple-station, or multiple-position twisting machines, wherein at each station there is provided friction twisting means.
My above-mentioned Application Ser. No. 478,599, directed to adjustments in the amount of twist being applied at the various twisting stations, particularly independent adjustment from station-to-station is additionally and especially enhanced by the present development of a monitoring apparatus and technique. This monitoring, as it allows for independent monitoring and automatic independent adjustment of the amount of twist at each station, on an independent station-to-station basis is particularly desirable.
More specifically, the particular monitoring technique of the present invention is a separate advance in itself. In U.S. Pat. to Carruthers No. 3,613,347, a needle type of monitor is disclosed. The present invention utilizes a particularly unique monitoring technique of great sensitivity and durability, allowing for sliding of yarn over a surface, as opposed to a blade, as well as incorporating ready readjustability features for a desired helix angle setting.
Accordingly, it is a primary object of the present invention to provide a novel monitoring technique and the apparatus therefor.
It is a further object of the present invention to provide a novel technique and apparatus for employing a monitor in conjunction with an adjustable twist-inducer, the latter being automatically responsive to the monitor.
It is another object of this invention to accomplish the above object, on a plurality of stations of a machine, whereby the monitoring and the adjustment is independent from station-to-station, or from position-to-position.
It is a further object of this invention to utilize a monitor as applied to friction twisting, to monitor the amount of twist, while employing sensitive switching techniques.
It is a further object of this invention to accomplish the above objects, wherein a magnetic switch is employed.
It is another object of this invention to provide apparatus and technique for enhancing yarn uniformity on a station-to-station basis, as it relates to twist being applied to yarn at those stations, and to do so at any given station independently of other stations.
It is a further object of this invention to provide a novel construction for a twist-inducing wheel in accordance with the present invention.
Other objects of the present invention will be readily apparent to those skilled in the art by reading the following brief descriptions of the drawing figures, detailed descriptions of the preferred embodiments, and the appended claims.